Effects of hormone receptor status on patient clinic and survival in HER2 positive breast cancer

Background In the current study, the effect of hormone receptor (HR) status on clinical and survival in early-stage human epidermal growth factor receptor 2 (HER2)-positive breast cancer was investigated. Methods Two hundred ninety-one patients with HER2- positive were examined in two categories as HR-positive and HR-negative. Results Of these, 197 (68%) were HR-positive and 94 (32%) were HR-negative with a mean follow-up period of 68 +/- 2.7 months. The groups were found to be similar in terms of age, menopausal status, comorbidity, pathologic type, stage, T stage, N stage, lymphovascular invasion, presence and percentage of intraductal component, multicentricity/focality and extracapsular invasion. Family history (P = 0.038), stage 2 tumor rate (P < 0.001), and perineural invasion (P = 0.005) were significantly higher in the HR-positive group. In the HR-negative group, mean Ki-67 value (P = 0.014), stage 3 tumor rate (P < 0.001), tumor necrosis (P = 0.004) and strong (3+) HER2 staining on immunohistochemical staining (P = 0.003) were higher. The incidence of relapse and metastasis, and the localization of metastasis were similar in both patient groups. The rate of locoregional relapse during the first 2 years was higher in the HR-negative patients than in the HR-positive patients (P = 0.023). Overall survival (OS) and disease-free survival (DFS) did not differ between the groups in univariate analysis. However, HR status was determined as an independent prognostic factor (HR: 2.11, 95% CI: 1.17-3.79; P = 0.012) for OS was not found to be significant for DFS in multivariate analysis. Conclusion Both clinicopathologic features and OS outcomes of HR-negative patients were worse than those of HR-positive patients.